<template>
  <div class="list" ref="wrapper">
    <div>
       <div class="area">
        <div class="title border-topbottom">当前城市</div>
        <div class="button-list">
          <div class="button-wrapper">
            <div class="button">
              {{this.cureentCity}}
            </div>
          </div>
        </div>
      </div>
      <div class="area">
        <div class="title border-topbottom">热门城市</div>
        <div class="button-list">
          <div class="button-wrapper" v-for="item of hot" :key="item.id" @click="handleCityClick(item.name)">
            <div class="button">
              {{item.name}}
            </div>
          </div>
        </div>
      </div>
      <!-- 标记ref 识别dom元素 -->
      <div class="area" v-for="(item, key) of cities" :key="key" :ref="key">
        <div class="title border-topbottom">{{key}}</div>
        <div class="item-list">
          <div class="item border-bottom" v-for="innerItem of item" :key="innerItem.id" @click="handleCityClick(innerItem.name)">
          {{innerItem.name}}
          </div>
        </div>
      </div>
    </div>
  </div>
</template>
<script>
import Bscroll from 'better-scroll'
import { mapState, mapMutations } from 'vuex'

export default {
  name: 'CityList',
  props: {
    hot: Array,
    cities: Object,
    // 接收父组件传递过来的参数
    letter: String
  },
  computed: {
    ...mapState({
      cureentCity: 'city'
    })
  },
  // 监听
  watch: {
    // 接收父组件传递过来的参数监听变化
    letter: function () {
      if (this.letter) {
        // 定义ref获取元素dom
        const element = this.$refs[this.letter][0]
        // 滚动到指定dom元素位置
        this.scroll.scrollToElement(element)
      }
    }
  },
  methods: {
    handleCityClick (city) {
      this.changeCity(city)
      this.$router.push('/')
    },
    ...mapMutations(['changeCity'])
  },
  mounted () {
    this.scroll = new Bscroll(this.$refs.wrapper, { click: true })
  }
}
</script>
<style lang="stylus" scoped>
@import '~styles/varibles.styl'
.border-topbottom
  &:before
    border-color #ccc
  &:after
    border-color #ccc
.border-bottom
  &:before
    border-color #ccc
.list
  overflow hidden
  position absolute
  top 1.58rem
  left 0
  right 0
  bottom 0
  .title
    line-height .54rem
    padding-left .2rem
    background #eee
    color #666
    font-size .26rem
  .button-list
    overflow hidden
    padding .1rem .6rem .1rem .1rem
    .button-wrapper
      float left
      width 33.33%
      .button
        margin .1rem
        padding .1rem 0
        border .02rem solid #ccc
        text-align center
        border-radius .06rem
  .item-list
    .item
      line-height .76rem
      padding-left .2rem
</style>
